Daily Endocrinology Research Analysis
Analyzed 89 papers and selected 3 impactful papers.
Summary
Analyzed 89 papers and selected 3 impactful articles.
Selected Articles
1. A skin-hypothalamus axis couples heat stress and metabolic dysfunction.
This mechanistic study identifies a previously unrecognized skin–hypothalamus axis whereby heat stress elevates skin KLK14, imprints hypothalamic signaling, and heightens susceptibility to diet-induced metabolic dysfunction. The work links environmental heat exposure to long-term metabolic risk via a neuroendocrine pathway.
Impact: Revealing a cross-organ stress axis that couples skin signals to hypothalamic control represents a paradigm-advancing mechanism with broad implications for metabolic disease in a warming climate.
Clinical Implications: While preclinical, the findings suggest at-risk populations during heat waves may benefit from targeted mitigation (cooling strategies) and raise prospects for therapeutics modulating KLK14–hypothalamic signaling to prevent metabolic deterioration.
Key Findings
- Heat-stressed mice developed greater metabolic dysfunction after subsequent obesogenic diet exposure.
- Heat stress elevated skin-derived KLK14 and imprinted hypothalamic signaling (LRRC7 pathway indicated).
- Defines a novel skin–hypothalamus axis linking environmental heat to metabolic disease susceptibility.
Methodological Strengths
- Rigorous in vivo mechanistic framework linking environmental exposure to neuroendocrine remodeling.
- Multi-level interrogation of peripheral (skin) to central (hypothalamus) signaling.
Limitations
- Findings are preclinical and require validation in human systems.
- Specific molecular intermediates and causal sufficiency of KLK14–LRRC7 signaling need full delineation.
Future Directions: Translate to human models (biomarkers of skin–hypothalamus signaling under heat exposure), test KLK14 or downstream pathway inhibitors, and evaluate interactions with obesity/age/sex.
With the ongoing rise in global temperatures, the prevalence of heat-stress-related chronic health disorders has increased. However, whether heat stress has an enduring impact on metabolic health remains unclear. Here, we report that mice exposed to heat stress were more susceptible to metabolic dysfunction upon subsequent exposure to an obesogenic diet. Upon heat stress, we found that elevated skin-derived kallikrein-related peptidase 14 (KLK14) imprinted hypothalamic LRRC7
2. The N-terminus of Apolipoprotein B mediates the interaction of atherogenic lipoproteins with endothelial cells.
Using structural mapping and functional assays, the study shows distinct N-terminal APOB motifs engage SR-BI and ALK1 on endothelial cells. An APOB18 fragment blocks endothelial uptake/transport of atherogenic lipoproteins and, when overexpressed, reduces atherosclerosis in hypercholesterolemic mice, nominating a tractable anti-atherosclerosis target.
Impact: Defines precise receptor-interacting APOB motifs and demonstrates in vivo atherosclerosis mitigation, opening a peptide/biologic strategy to curb endothelial lipoprotein flux.
Clinical Implications: If translatable, APOB N-terminal mimetics or inhibitors of APOB–SR-BI/ALK1 interactions could complement lipid-lowering to reduce residual cardiovascular risk by limiting arterial wall lipoprotein entry.
Key Findings
- Distinct N-terminal APOB regions mediate binding to SR-BI and ALK1 on endothelial cells.
- APOB18 (N-terminal 18%) reduced endothelial uptake/transport of chylomicrons and LDL; APOB12 selectively blocked ALK1-mediated uptake of APOB100 lipoproteins.
- Endothelial-targeted overexpression of APOB18 decreased atherosclerosis in hypercholesterolemic mice.
Methodological Strengths
- Convergent evidence from molecular modeling, mutagenesis, cell uptake/transport assays, and in vivo mouse atherosclerosis.
- Receptor specificity dissected using APOB fragments and receptor expression systems.
Limitations
- Translation from overexpression and peptide-fragment models to human therapeutics remains uncertain.
- Potential off-target effects or compensatory endothelial pathways were not fully explored.
Future Directions: Develop stabilized APOB18-derived inhibitors, evaluate pharmacokinetics/safety, and test efficacy in larger animal models and human endothelial systems.
Apolipoprotein B (APOB) containing lipoproteins contribute to atherosclerosis by entering the arterial wall through the endothelial cell (EC) surface receptors scavenger receptor-BI (SR-BI) and activin receptor-like kinase 1 (ALK1). We used N-terminal fragments of APOB, molecular modeling, and site-directed mutagenesis to identify and block the binding of chylomicrons and LDL to these receptors in cells and mice. We discovered that different APOB regions interact with SR-BI and ALK1 expressed on ECs APOB48 lipoproteins were only internalized by SR-BI. A fragment of APOB, comprising 18% of the N-terminal sequence, APOB18, reduced the uptake and transport of both chylomicrons and LDL by ECs, whereas a shorter fragment, APOB12, only blocked ALK1 mediated uptake of APOB100 containing lipoproteins. Importantly, overexpressing APOB18 decreased atherosclerosis in hypercholesterolemic mice. These findings identify the N-terminal region of APOB as the cause of atherosclerosis and illustrate an approach to treating or preventing vascular disease.
3. Forearm BMD predicts fracture independently of FRAX.
Across 11 cohorts (N=35,121; mean follow-up 11.1 years), lower forearm BMD predicted major osteoporotic and hip fractures independently of FRAX probabilities calculated without BMD. The gradient of risk attenuated with age, supporting age- and Z score–tailored adjustment of FRAX using forearm BMD.
Impact: Provides international-level validation that forearm DXA augments fracture risk stratification beyond FRAX, enabling broader case finding where hip DXA is unavailable or in specific clinical scenarios.
Clinical Implications: Clinicians can integrate forearm BMD into fracture risk assessment, adjusting FRAX probabilities particularly in settings lacking femoral neck BMD, and consider age-specific GR when interpreting results.
Key Findings
- Forearm BMD predicted major osteoporotic fracture with GR 1.41 (95% CI 1.31–1.51) after age/time adjustment.
- Prediction persisted after adjustment for FRAX MOF probability (GR 1.34; 95% CI 1.26–1.44).
- Similar independent prediction for hip fracture (GR 1.39 after FRAX adjustment), with GRs decreasing with age.
Methodological Strengths
- Large-scale, multi-cohort analysis with individual-level modeling and standardized GR estimates.
- Adjustment for FRAX probabilities and exploration of age/Z-score effects increase generalizability.
Limitations
- Heterogeneity in cohort protocols and BMD acquisition sites may influence pooled estimates.
- FRAX computed without femoral neck BMD; integration algorithms for clinical use require implementation guidance.
Future Directions: Prospective validation of age- and Z score–dependent FRAX adjustments using forearm BMD and assessment of cost-effectiveness and implementation in diverse care settings.
UNLABELLED: The relationship between bone mineral density (BMD) at the forearm and fracture risk was determined in a meta-analysis of primary data from 11 cohort studies of 35,121 men and women. Low forearm BMD was a significant predictor of fracture risk, independently of FRAX®. INTRODUCTION: The aim of this study was to quantify the relationship between forearm BMD, FRAX and fracture risk and examine the effect of age, sex, time since measurement, and initial BMD value on fracture risk. METHODS: We studied 35,121 men and women from 11 predominantly population-based cohorts followed for an average of 11.1 years and a total of 388,654 person-years. The association between forearm BMD, FRAX probabilities (calculated without femoral neck BMD), and the risk of fracture was examined using an extension of the Poisson regression model in each cohort by sex and expressed as the gradient of risk (GR; hazard ratio per 1 SD difference in BMD). The different studies were merged using weighted coefficients. RESULTS: The GR of forearm BMD for major osteoporotic fracture was 1.41 (95% confidence interval [CI] 1.31-1.51) when adjusted for age and time since baseline and was similar in men and women (p > 0.20). GRs decreased significantly with age. When additionally adjusted for FRAX 10-year probability of major osteoporotic fracture, forearm BMD remained a significant, independent predictor for fracture (GR = 1.34, 95% CI 1.26-1.44). A similar GR was noted for hip fracture (GR = 1.48; 95% CI 1.35-1.62) that persisted after adjustment for FRAX (GR = 1.39; 95% CI 1.27-1.52). Adjustments to FRAX probabilities based on forearm BMD varied by age and Z-score. CONCLUSIONS: Forearm BMD is a risk factor for MOF and hip fracture risk beyond the risk attributable to FRAX. Its validation on an international basis permits its use in case finding with FRAX.